(01-09-2017 05:29 PM)PANAMATIK Wrote: ..... if you wait for my HP-25E Low Power circuit, which will be available end of spring. The schematic is in its final stage. Main features are 20-40mA when display is on, Microamps when in standby mode, full Continuous memory like the LCD models, USB connector for program upload, download, 512k Flash memory, enough for all models in one, Real Time Clock, Buzzer, Infrared printing, easy to install by inserting it below the display area.

Bernhard

As you can see above by quoting myself, I announced the "HP-25E Low Power" circuit in january with lots of features. But it turned out, that this circuit was very ambitious and I questioned more and more whether it would make sense to build it. The small space below the LED display would urge me to produce a four layer PCB and my costs would be rather high compared to the expected low demand for this circuit.

So I decided not to go on with this project. I'm sorry. The main idea was to offer a circuit, which could repair also "Woodstocks" with defective display drivers. But I did not get any feedback report, that a calculator could not be repaired with the newACT. Obviously defective display drivers are very rare compared to defective ACTs.

The newACT chip will remain the only repair chip, which I will produce. It has the most important basic capabilities needed, and will stay available as long as "Woodstock" calculators need a repair.

Printing with the HP-67 is not a new feature of the new ACT. But for the first time I upgraded my own HP-67 by installing the infrared printing diode. Read the ACT Manual Rev 1.11, it contains a new chapter, which describes how this is done.

I drilled a 3 mm hole into the front. Then the two wires of the diode can be placed very elegantly along the left side of the case and soldered to the HP-67 processor board, connecting it to the new ACT. This installation is very easy and you can print your programs and trace your calculations with an HP-67 likely the same as with the HP-97 desktop printer.

The final result shows a nicely placed small IR LED and a printout of the first lines of the original HP-67 Moon Lander program.

Thanks to teenix an HP-29C original firmware patch was made to remove a 40 year old bug. The HP-29C has a firmware bug, which needed a long key press to stop a program during PAUSE. Now only a short key press is necessary like in any other "Woodstock" calculators and in the twin calculator HP-19C.

I made a modified version for the HP-29E available. You can download actupdate if you want to update your HP-29E.

I just released a new version of the HP-25E ACT for download and update. There are no bug fixes with respect to the previous version, but three remarkable new features.

1.) Multitasking

You can run your program in the background and play with all other functions like stopwatch and the built in extended functions. This gives you the possibility to play with your calculator or measure program runtimes, while your program is independently running.

2.) No display flicker anymore

While programs are running, the HP-25 and all LED calculators showed their characteristic display flicker, this can be switched off and replaced by a steady display, which shows the last intermediate result, even after the PAUSE command is finished. Only a small dot is blinking to indicate a running program. I think You can't underestimate this improvement.

3.) Detailled program and register usage map

As the HP-25E offers 110 programs and 88 registers, it was overdue to provide a detailled map of occupied and free registers and programs. This function replaces the memory summary display. The free memory summary is still available by an even shorter key sequence.

Would it be possible to build in a "View" functionality to complement the PAUSE function?

If you activated flicker suppression and then did a VIEW function, instead of merely displaying the paused value for a second or so, it would display the view value until another view, pause or end of program.

Would it be possible to build in a "View" functionality to complement the PAUSE function?

If you activated flicker suppression and then did a VIEW function, instead of merely displaying the paused value for a second or so, it would display the view value until another view, pause or end of program.

(07-25-2017 12:24 AM)Gene Wrote: Ah, sorry. I thought it did not flicker but then a PAUSE would show the result for a second and then go blank or such again.

Good... glad it does what it does!

Of course, your idea is the only that makes sense. The ACT detects each PAUSE instruction, then latches the display contents until the next PAUSE or until the program is stopped. As a side effect of implementing this feature PAUSE will now be prolonged in fast execution mode and last always 1 s, same as in original speed.

You can run your program in the background and play with all other functions like stopwatch and the built in extended functions. This gives you the possibility to play with your calculator or measure program runtimes, while your program is independently running.

I like to mention that this feature came into my mind by an observation of Horst Hoffmann when testing his HP-29E. He could invoke the stopwatch during a PAUSE instruction, because the original HP-29C firmware ignored keystrokes during the PAUSE command and didn't stop. Now it was easy to go a step further and hide all keystrokes (except R/S) from the emulator, when a program was running.

Special thanks to Horst for beta testing and making useful observations.

Many Woodstock calculators have been repaired with the "new ACT" since the start of this project two years ago. Many program lines have been written for this small chip.

Now I decided to publish the source code of the latest version HP25E 1.13. It is complete for compiling all possible variants of HP calculators.

If you want to have an insight of how the "new ACT" firmware looks like, just open the files and read comments and try to understand the intended code.

I apologize for the exceptionally cryptic code, which uses assembler parts and many (too many) compiler switches. It is the result of the highly optimized code due to the space limitations of the PIC16F1518 chip and so many ideas, which had to be implemented.

I added lots of comments, but still the code remains nearly unreadable (the same reason why microsoft didn't published its source code, right?). I apologize again.

Change the files to your needs and use the Microchip xc8 compiler, if you want to build the project. But I cannot give you more support than the files tell themselves.

Very interesting !.
Maybe I can find out why pressing R/S SST or BST for a while doesn't seem to work on my fpga version. Even if I cleared the flag 3 and re-scan the keyboard. I'm missing something there.

(10-03-2017 05:32 AM)Alejandro Paz(Germany) Wrote: Very interesting !.
Maybe I can find out why pressing R/S SST or BST for a while doesn't seem to work on my fpga version. Even if I cleared the flag 3 and re-scan the keyboard. I'm missing something there.

Auf jedem fall: Große Vielen Dank !

As long as any key is pressed set its keycode to the keybuffer register and set bit 15 of the status register before each instruction is executed. If no key is pressed reset bit 15 of the status register. Then R/S SST and BST should work.

I don't know what flag 3 does in your code. This is not an ACT register.

I used a hand-shake mechanism between the keyboard and the CPU. At some point I changed how key presses were recognized to save some flops as the whole was not fitting in the 1280 LUT fpga. I'll look again, because things like Error clear work properly.

The "new ACT" for the real HP-67 calculator has got a major update version 1.14. It shows a much improved memory usage display, lots of texts like operating hours, serial number use separate digits for the decimal dot and make use of the 15-digit display. And of course some bug fixes.

For the first time there is the possibility to integrate a GPS receiver into the HP-67.

Also 10 of the 15 STANDARD PAC application programs are preloaded, using 10 of the available 21 user programs. But they can be overwritten by your own programs.

Like in previous versions 160 additional registers are included in the new version 1.14 (GPS version only 16), stopwatch (and hex conversion only without Ir and GPS) are included. All these versions can be downloaded from my website, see actupdate

This image shows the UTC time received from GPS satellites. The HP-67 display drivers cannot display the letter "P", therefore a 180 degree turned "d" letter is used for "Global Discovery System"

The GPS module fits very tight as shown here near the Card reader motor, but housing can be closed normally. The motor can also be removed for getting more space.

The switching power supply for getting 3.3 Volt from the batteries is nicely placed on the bottom side of the main board and some wiring is necessary. The red and black wires leads to the Infrared printing diode, which can be used coexistent with the GPS.

The GPS version for the HP-67 was inprired by a member here and I'm very grateful for it, because I could equip my own HP-67 now with a GPS module and it gives me much fun (added to the hard work for getting the software running, which was also fun)